xxhash.nim

xxhash wrapper for Nim This is a wrapper for the xxhash hashing library in Nim, which provides fast, non-cryptographic hashing for various use cases such as file integrity checks, data storage, and more.

Features

• Supports XXH32, XXH64, and XXH128 hashing algorithms.
• Designed to work seamlessly with the Nim language.
• Efficient and fast hashing suitable for performance-sensitive applications.

Installation

To use xxhash.nim, install the library using Nimble:

nimble install xxhash

Alternatively, you can clone the repository from the official source and add it to your project manually.

Basic Usage

Below is a simple example of how to use the xxhash library in a Nim project.

Importing the Module

import xxhash

Hashing a String

To compute a 32-bit hash of a string using XXH32:

let hash32 = XXH32("Hello, world!")
echo hash32

To compute a 64-bit hash using XXH64:

let hash64 = XXH64("Hello, world!")
echo hash64

For larger data or more security, use XXH128:

let hash128 = XXH3_128bits("Hello, world!")
echo hash128

Hashing a File

To hash a file, you can use:

import os

let fileContent = readFile("path/to/file")
let fileHash = XXH64(fileContent)
echo fileHash

Streaming Hash Computation

For large files or streams, the xxhash library provides stateful hashing that allows hashing in chunks. Here's an example using XXH64:

var state = newXxh64()

# Process in chunks
state.update("Hello, ")
state.update("world!")

let finalHash = state.digest()
echo finalHash

# Important: Free the state after use in Nim 1.x.x
state.free()

Note for Nim version 1.x.x

In Nim versions older than 2.0.0, you should manually call state.free() to deallocate resources because Nim does not automatically call destructors (=destroy). This step is crucial to avoid memory leaks when using the stateful API.

Performance Considerations

• xxhash is designed to be very fast and is optimized for bulk data processing.
• XXH128 is slightly slower but provides more robust hashing for larger datasets.

Additional Information

This wrapper supports both 32-bit and 64-bit systems, ensuring compatibility across various platforms.

Credits

• This module utilizes @rockcavera's nint128 for XXH128 computation.

License

This project is distributed under the MIT License.

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